water and can clean more effectively in hard water than soap. ¾ can also be used in saline and acidic water. ¾ do not leave any soap scum on the tub or clothes. ¾ dissolve freely even in cool water and rinse freely in hard water.
¾ can be used for washing woollen garments, where as soap cannot be used. ¾ have a linear hydrocarbon chain, which is biodegradable. ¾ are active emulsifiers of motor grease. ¾ do an effective and safe cleansing, keeping even synthetic fabrics brighter and whiter.
Biodegradable and Non-biodegradable detergents: a) Biodegradable detergents: They have straight hydrocarbon chains, which can be easily degraded by bacteria. Hydrophilic head Hydrophobic tail Aqueous solu on Soap molucules Soap solutoin Dirt Dirty cloth Figure . Cleansing action of soap b) Non-biodegradable detergents: They have highly branched hydrocarbon chains, which cannot be degraded by bacteria. Disadvantages of Detergents .
Some detergents having a branched hydro- carbon chain are not fully biodegradable by micro-organisms present in water. So, they cause water pollution. . They are relatively more expensive than soap.
Carbon and its Compounds . . Comparison between soap and detergents Soap Detergent It is a sodium salt of long chain fatty acids. It is sodium salts of sulphonic acids.
The ionic part of a soap is – COO – Na + . The ionic part in a detergent is – SO – Na + . It is prepared from animal fats or vegetable oils. It is prepared from hydrocarbons obtained from crude oil.
Its effectiveness is reduced when used in hard water. It is effective even in hard water. It forms a scum in hard water. Does not form a scum in hard water.
It has poor foaming capacity. It has rich foaming capacity. Soaps are biodegradable. Most of the detergents are non-biodegradable.
Have you noticed the term "TFM" in soap TFM means TOTAL FATTY MATTER. It is the one of the important factors to be considered to assess the quality of soap. A soap, which has higher TFM, is a good bathing soap. Points